Among adolescents, iron-deficiency anaemia is one of the most
common diet-related deficiency diseases. Adolescents are particularly
susceptible to iron deficiency anaemia in view of their increased blood volume
and muscle mass during growth and development. This raises the need of iron for
building up haemoglobin, the red pigment in blood that carries oxygen, and for
the related protein myoglobin, in muscle. The increase in lean body mass (LBM),
composed mainly of muscle, is more important in adolescent boys than in girls.
In preadolescent years, LBM is about the same for both sexes. Once adolescence
starts, however, the boy undergoes a more rapid accumulation of LBM for each
additional kilogram of body weight gained during growth, ending up with a final
LBM maximum value double that of the girl. Other factors contributing to
elevated iron needs are increased body weight and the beginning of menstruation
for girls. All these factors should be taken into account when assessing iron
needs in this group of age.
One of the most important diet considerations during adolescence
is an increase in the intake of iron-rich foods such as lean meats and fish as
well as beans, dark green vegetables, nuts and iron-fortified cereals and other
grains. Iron from animal foods (known as haem iron) is much better absorbed
than iron from non-animal sources (non-haem iron). Adolescents
following vegetarian diets are therefore at an increased risk of iron-deficiency.
However, vitamin C (e.g. from citrus fruits) and animal proteins (meat &
fish) assist in the absorption of non-haem iron.
